A method for obtaining plural element chips that divides an element-group formation substrate, in which plural electronic elements are formed on a substrate, into individual pieces is widely used.
As a conventional technique described in a gazette, there is a technique in which modified regions are formed inside a semiconductor substrate, such as a silicon wafer, by focusing laser light inside the semiconductor substrate and performing irradiation, to form a first expected cutting portion with the modified regions in a first direction, and other modified regions are formed inside the semiconductor substrate by focusing laser light inside the semiconductor substrate and performing irradiation to form a second expected cutting portion with the modified regions in a second direction that intersects the first direction (refer to Patent Document 1).
In addition, as another conventional technique described in a gazette, there exists a technique in which, in a production method that forms individual group III nitride-based compound semiconductor elements by dividing a sapphire substrate on which a group III nitride-based compound semiconductor is laminated, at least two stages of work modifying portions (break lines) are formed in a depth direction of the sapphire substrate by focusing pulse laser inside the sapphire substrate and on an expected dividing plane to divide into chips (refer to Patent Document 2).